1. Field of the Invention
The present invention relates to a quick coupling element for releasably connecting together two pipes. Such a male or female element is designed to be coupled to a complementary female or male element in order to put two pipes of fluid under pressure into communication. The invention also relates to a quick coupling including, amongst other elements, such a coupling element.
2. Description of the Related Art
Generally, the male and female elements of a quick coupling are coupled together by aligning a longitudinal axis of the male element on a longitudinal axis of the female element. In certain applications, these male or female elements are mounted on plates that are moved by robots. This applies in particular in applications for circulating cooling fluid, e.g. in the field of molding parts out of plastics material. Such a technique can also be used for coupling pipes together under water. It can happen that the longitudinal axes of the two elements of a coupling that are to be coupled together are laterally offset relative to each other. To mitigate that difficulty, it is known, e.g. from US 2005 164538, to use a coupling element that is mounted to pivot relative to a body, thereby enabling leaktight coupling to be obtained in spite of not being in alignment.
In certain couplings with a pivoting coupling member, the axial position of the coupling member in the corresponding body depends on the fluid pressure present in an upstream pipe connected to the coupling element, with a sealing gasket serving solely to bring the coupling element towards a middle position on uncoupling. While a male element is being coupled in a female element, torque is generated by friction, with such friction-generated torque increasing with increasing pressure of the fluid present in the pipes connected to the coupling element that includes the coupling member, said torque opposing pivoting of the coupling member. This friction torque is exerted via a contact zone between the coupling member and the body of the coupling element, which contact zone is formed on the front of the coupling member, i.e. on a portion of said member that faces towards the other coupling element. The friction force is thus exerted at an axial distance from the hinge point between the coupling member and the body, which distance is relatively long, such that the friction force exerts a considerable opposing torque. Thus, in the event of non-alignment between the end of the male element of a coupling and the female element a high level of torque needs to be exerted in order to enable the coupling member to pivot and coupling to take placed with the complementary female element, thereby leading to premature wear on the entry surface of the female element and on the peripheral surface of the male element. The reliability and the lifetime of the coupling are thus decreased. Furthermore, this limits the amount of misalignment that the quick coupling including such a prior art coupling is capable of accommodating.